1. Background of the Invention
The technical sector of the present invention is that of lighting modules capable of generating a light beam. Such a lighting module has a particular application in a lighting and/or signaling device for a vehicle, in particular an automobile.
2. Description of the Related Art
Automobiles are conventionally equipped with a lighting and/or signaling device, referred to as a lamp unit. These use a light source which, until recently, has been produced by means of an incandescent lamp.
A new light source technology is replacing these incandescent lamps: that of light-emitting diodes. These are capable of providing a sufficient lighting performance for signaling and lighting functions, and have the advantage of being small. When used as a light source, these light-emitting diodes also have the advantage of reducing the electricity consumption compared with the same optical function performed by an incandescent lamp. The reasons why automobile manufacturers are eager for this new technology can therefore be understood from this.
These light-emitting diodes release heat, and it is therefore necessary to ensure dissipation of this heat in order to ensure correct operation and the long life of this type of light source. In order to do so, it is known to place these light-emitting diodes close to a heat sink, the combined assembly being installed inside the lamp unit.
Furthermore, these light-emitting diodes are driven electrically by a control device installed in proximity to the assembly mentioned above. According to a first solution known from the prior art, the control device and the light-emitting diodes are placed together on the same printed circuit board, the board then being coupled to the heat sink.
This solution has certain drawbacks. Specifically, combining the control device and the light-emitting diodes on the same printed circuit board requires a large area, because it is necessary to ensure cooling both of the light sources and of the components of the control device. The heat sink is then large, and this size causes difficulties of integration inside the volume of the lamp unit, this volume being particularly restricted.
According to another solution known from the prior art, it has been proposed to install the control device separately from the light sources. Such a solution requires the use of a cable, which the operator in charge of assembling the lamp unit connects on one side to the light sources and on the other side to the control device. This connection is then ensured by means of electrical connectors, of which a male part is secured to the cable while a female part is fixed level with the light sources and the control device.
This solution also has drawbacks. Specifically, because of the weight of each of the components electrically connected by the cable, it requires an electrical connection carried out manually once the light sources and the control device have been secured to the lamp unit. Such an operation is a source of faults, such as a loss of electrical connection due to vibrations or impact, which leads to late rejection of the lamp unit, for example during assembly on the vehicle or when the vehicle is being driven. Furthermore, it is necessary to manage three pieces on the assembly line of the lamp unit, that is to say the lighting module, the cable and the control device. This leads to logistical complications. Lastly, this solution involves the use of plug-in electrical connectors, which represent a nonnegligible cost in the lighting function.